Advancing supporting device for walking mine-supporting constructions



Nov. 16, 1965 K. M. GROETSCHEL 3,217,498

ADVANCING SUPPORTING DEVICE FOR WALKING MINE-SUPPORTING CONSTRUCTIONS Filed March 21. 1961 4 Sheets-Sheet 1 awn/rap KARL MARIA GROETSCHEL.

ATTORNEY 7 Nov. 16, 1965 M. GROETSCHEL 3,217,498

K. ADVANCING SUPPORTING DEVICE FOR WALKING MINE-SUPPORTING CONSTRUCTIONS Filed March 21, 1961 4 Sheets-Sheet 2 [N v EN ro KARL MARIA GROETSCHEL ATTORNEY Nov. 16, 1965 K. M. GROETSCHEL 3,217,493

ADVANCING SUPPORTING DEVICE FOR WALKING MINE-SUPPORTING CONSTRUCTIONS Filed March 21, 1961 4 Sheets-Sheet 5 KARL MARIA GROETSCHEL WM/W ATTORNEY K. M. GROETSCHEL 3,217,498 ADVANCING SUPPORTING DEVICE FOR WALKING MINE-SUPPORTING CONSTRUGTIONS Nov. 16, 1965 4 Sheets-Sheet 4 Filed March 21, 1961 VVENTOR KARL MARIA GROETSCHEL United States Patent 19 Claims. (Cl. 61-45) This invention relates to an advancing roof support system which is operated by a pressure medium, preferably hydraulically, for walking supporting structures in underground coal and mineral mining, i.e., a prop, and a support stand or frame which carries at least one roof bar which by means of a hinge connection is connected to said stand or frame or to a roof bar carried thereby, said roof bar being adapted to be cantilevered while being secured against downward deflection by unilateral locking of the hinge.

Such supporting devices, which have particularly advantageous properties from the aspect of their intended use, namely extensive mechanisation or automation of the setting and advancing process while the roof is completely secured by the cantilevered bar or bars, are known per se.

The object of the invention is to improve such supporting devices still further as regards their purposes of use, and in particular make the entire setting and advancing processes completely reliable and automatic.

In such supporting devices it is already known to use a pressure cylinder to operate the device which cantilevers the bar and which locks the hinge. This known arrangement, however, only enables the bar to be swung up and the swung-up bar to be locked, but it does not enable the cantilevered bar to be swung down, although in some cases this is much more important.

The invention provides an operating device which enables not only the upward but also the downward movement of the advance bar to be controlled according to plan, independently of the hydraulic system with which the props of the support stand or of some other supporting device may be provided, i.e., irrespective of the conditions of the supporting system from which the advance bar is cantilevered, i.e., that of loading by the roof or the retracted state of the props. The new device is also suitable both for operation of only one and for the simultaneous or consecutive operation of two adjacent bars. Moreover, it may be particularly advantageously combined with any advancing cylinder with which the supporting device is provided, so that a predeterminable sequence of the various processes to be performed by these devices is obtained, so that, in particular, the dangers indicated in detail hereinbelow and resulting from the possible operation of the advancing cylinders before the bar or bars have been swung down, are eliminated.

According to the basic principle of the invention, a reversible pressure cylinder, preferably a hydraulic cylinder, is provided on the supporting element in the axial direction of the bar locking element, which latter is preferably constructed in the form of a wedge or slide, and in one direction of movement the piston rod or cylinder body of the said pressure cylinder acts on the locking element so as to release it from its operative position and hence so as to lower the bar while in the other direction of movement it brings the locking element into the operative position and hence swings the bar upwards and acts so as to press it against the roof.

The connection between the locking element and the piston rod or the cylinder of this operating device which forms an independent element and which is preferably 3,217,498 Patented Nov. 16, 1965 formed by parts which are independent of components of the support stand or the like is preferably effected with the cylinder disposed directly in line with the locking element. If, for reasons of space, the device is disposed at a distance from the locking element and parallel thereto, its action on the locking element is eifected either through a projection on the said locking element and preferably forming a unit therewith, or through a linkage formed from two sleeves, each of which is pro vided with a projection and which are guided on the cylinder, or from double levers which are pivotally connected to the pressure device and to the locking elements to be operated.

When this arrangement is used to operate the locking elements of two bars disposed adjacent one another on the support stand or the like, then if the locking elements are constructed to act in opposition to one another, operation of the pressure device moves the two elements in the locking or releasing direction until each has reached its respective end position.

The double-action construction of the hydraulic or pneumatic pressure device has the advantage over the provision of restoring springs that the pressure piston can be controlled according to plan and, in particular, it ensures release of the locking element without any additional manual operation even if said locking element is deformed by over-loading to such an extent that its free movability is obstructed.

The double-acting pressure device will therefore be used particularly for bars of the kind which according to a particular feature of the invention have a planned weak point, the locking elements being so constructed to protect the other parts of the connection that they yield in the event of an overload, but only after the weak point of the bar has acted as an initial means of security.

The provision of double-acting independently controllable cylinders which are not connected to the pressure chambers of the hydraulically extensible supporting device itself enables each individual bar to be separately relieved and swung down and also enables the reverse process to be carried out equally independently. This possibility may be very desirable if a correction or addition, for example the subsequent insertion of a lagging, has to be carried out after the completion of advancing and replacing of the support stand or the like only at one or other advance bar.

The fact that the pressure cylinder or cylinders which, as such, can easily be installed and removed, are independent of the support stand or the like itself, enables them to be advantageously changed at any time.

The provision of the operating cylinder or cylinders transversely of the longitudinal direction of the bar necessitates a corresponding amount of space in the transverse direction and may lead to difiiculty particularly in the case of supporting elements which are constructed of single or double frames and from which the bars are cantilevered, if such frames have to be set without any spacing or else only very little spacing between them, because the space required for the cylinder or cylinders is then no longer available in the direction of the width.

According to an embodiment of the invention which may then be more advantageous, these difiiculties can be obviated by disposing the pressure cylinder or cylinders, not in the transverse direction, but in the longitudinal direction of the bar, beneath a part which is carried .by the supporting device and which projects beyond the latter, for example a bar carried directly by the supporting device.

In the case of this arrangement of the cylinder in the longitudinal direction of the bar, the locking element which by its displacement results in the pivoting of the advance bar may be a wedge element which is operated by the cylinder and which is mounted slidably in a pocket disposed on a part projecting from the supporting device.

According to a particular feature of the invention, this wedge element acts on the advance bar through a riderlike intermediate element which is mounted between boundaries, which guide it, of apertures in the side walls of a U-shaped pocket, and which can easily be changed and is constructed to be deformable to a certain degree, in order to create a weak point which thus protects the wedge element from wear on its working surfaces owing to excessive pressing in or deformation, and thus ensures that the cylinder will operate according to plan. To this end, the rider element may be of hollow construction. It preferably consists of two parts which are pivotal with respect to one another either directly or by way of a third element, the said parts thus continually adapting its function to the pivoted position of the bar.

According to another embodiment, the rider element itself is of expanding construction, with the elimination of another locking element, the device which effects its expansion and which acts on it being operated by the pressure cylinder.

The axial arrangement of the pressure cylinder for the element which effects the upward and downward swinging process and the locking action, beneath or inside a part projecting from the supporting device, and particularly the fact that the independence of the cylinder is not impaired by any rigid transverse connection between the said part and a part of a second support element, gives the possibility, according to another feature of the invention, of incorporating between the advance bar and the supporting device or the like a part which is extensible in relation thereto and the extension and retraction movements of which are preferably effected by a special cylinder likewise acting in the longitudinal direction of the bar.

The invention also covers the case when the entire cantilevering operation is effected from an intermediate bar which extends from the actual supporting device and which is in turn supported by a prop or pair of props.

The combination of an advancing cylinder which may be provided on the support stand or the like, and the operating cylinder or cylinders for the locking elements, which was already mentioned hereinabove as being a particularly essential feature of the invention, ensures that the advance bar is automatically lowered before the actual advance of the supporting element so that the bar is definitely in the lowered state when the operator brings the supporting device back against the roof after the advancing of said device.

Particularly in the case of a hydraulically operated supporting device it is absolutely essential that the advance bar should be in the lowered position before the extension of the extensible supporting device carrying it, because as a rule the stresses exerted during the extension operation which takes place with considerable force, for example, of a hydraulic support stand comprising a plurality of props, on a bar which is still at a high angle, when the top thereof or a presure transmission plate disposed thereon is pressed against the roof, may result in damage to the bar or to premature response of the weak point provided thereon as a means of protection against overload.

The invention obviates this danger by connecting the hydraulic cylinder, the piston of which operates the looking element effecting the upward and downward swinging movement of the bar, in parallel with the hydraulic system of the advancing cylinder used for advancing the support unit, and supplying pressure medium to the two cylinders from the feed line by Way of a single valve. The arrangement is made such that on the opening of the pressure medium supply line chambers one in each of the two cylinders are operated simultaneously, namely the chamber which moves the piston of this cylinder in the direction releasing the locking element is operated by the operating cylinder for the advance bar locking element or elements, while the advancing cylinder connected by its piston to the conveyor operates the chamber which effects the advance of the cylinder body and the supporting device attached thereto. In these circumstances, the piston surfaces of the two pistons operated simultaneously are so adapted to one another in the light of the work to be performed by the cylinders that the piston of the cylinder acting on the locking element is moved first.

The pressure fluid thus flows firstly solely to the cylinder provided for operation of the bar lock. Only when the resulting lowering of the advance bars has been completed, does the pressure fluid begin to become operative in the advancing cylinder and operate the latter. Swinging up of the bar is effected only after the advance of the supporting device and the extension of the latter thereafter.

The invention will be described hereinbelow with reference to the drawings which illustrate the application of the invention to support stands which carry advance bars connected to them by joints or advance bars connected to rearward bars which are likewise carried by the support stand, any details not necessary to an understanding of the invention having been omitted.

FIG. 1 is an elevational view of an embodiment of the invention,

FIG. 2 is sectional view of the apparatus of the invention taken along line 2-2 of FIG. 1,

FIG. 3 is a view similar to FIG. 2 showing another arrangement for mounting the actuating hydraulic cylinder,

FIG. 4 is a view similar to FIG. 3 showing still another arrangement for mounting the hydraulic cylinder,

FIG. 5 is a view of an arrangement for mounting two double acting hydraulic cylinders for effecting movement of associated locking members,

FIG. 6 is a plan view of an arrangement similar to that illustrated in FIGS. 2 and 4,

FIG. 7 is a view of apparatus showing another modification of the mounting of a double acting hydraulic cylinder,

FIG. 8 is a diagrammatic view of another modification of the invention,

FIG. 9 is a fragmentary view of another embodiment of the invention showing the hydraulic cylinder mounted in the longitudinal direction of the bar to be actuated,

FIG. 10 is a sectional view of the apparatus taken along line III-10 of FIG. 9,

FIG. 11 is a modified embodiment of the invention illustrated in FIG. 9,

FIG. 12 is an elevational view of another embodiment of the invention, and

FIG. 13 is a plan view of the apparatus illustrated in FIG. 12.

FIGURE 1 is a side view of an articulated bar 1 dis posed on a support stand (not shown), and a bar 3 cantilevered from this bar by means of the bolt-like locking lement 2, the locking element 2 being operated by the pressure cylinder 6" disposed outside the bar. In its end wall the advance bar 3 has a notch in which engages the inclined strip 5 of the bolt 2, the said strip 5 yielding in the event of any overload of the bar. A second identical bar arrangement at a distance therefrom may be imagined as being concealed by this drawing.

FIGURE 1 also shows in chain-dotted lines the possibility of constructing the advance bar as a leaf spring.

FIGURE 2 shows a hydraulic operating cylinder for the two slide-like locking elements 2', 2, which are disposed in opposition to one another, of the bars 1 and 4 which are shown only in cross-section on the line 2-2 in FIGURE 1, the cantilevered bars 3 corresponding to said locking elements being omitted.

The inclined strips 5', 5 of the bolts 2, 2 corresponding with the above-mentioned notches in the end wall of the advance bars are represented by the inclined rectangles shown in FIGURE 2 and in FIGURES 3, 4, 5 and 7.

According to FIGURE 2, each individual bar has associated with it a single hydraulic cylinder 6, 6", which is fastened detachably on the underside of their respective bar by means of piston rods 7" and 7", respectively. The pistons of these cylinders act on projections 8, 8' of the locking elements 2, 2' through the piston rods 7" and 7". The two single cylinders 6, 6", which may also be braced with respect to one another by way of a crossmember (not shown), are preferably connected together by way of the pressure medium line provided with appropriate control valves, so that they can be operated not only separately but also jointly in both directions.

FIGURE 3 shows an arrangement wherein a single cylinder 6 is connected beneath the bar 1 to the projection 8 on the locking element 2 therof, the piston rod of the said cylinder acting on the projection 8 of the locking element 2' of the bar 4. On operation of the cylinder, the piston and cylinder spread apart, with equalisation of the pressure exerted on the two locking elements.

FIGURE 4 is a diagrammatic view of a possible arrangement and construction of a power transmission linkage differing somewhat from that shown in FIGURE 2. It will be seen that here the arms which are to be moved by the pressure device 6 and which are pivotally connected to the locking element 2, 2 form a crank, the said arms accommodating the pressure cylinder between them and being directly connected by a joint at their opposite ends.

FIGURE 5 shows a possible arrangement of locking elements disposed to move in the same directions. In this case, two double-acting pressure cylinders 6', 6 are used in a parallel arrangement to the locking elements, the said pressure cylinders being connected with their end faces abutting one another and being held fast in the working direction by means of pins at the bar 1 and, as will be seen, being combined to form a single element. The piston rods of these cylinders act on projections 8, 8 on the locking elements. These cylinders may also be so controlled as to act jointly or independently of one another.

FIGURE 6 is a plan view of an arrangement similar to that shown in FIGURES 2 and 4. According to this embodiment, the locking elements 2, 2', which are mounted in opposition toone another, of the bars 1 and 4 are operated by way of a lever linkage disposed in the middle plane of the bars, by means of the pressure device 6, the piston rods 7, 7 of which pass with ample clearance through apertures 9, 9' provided in the bars. The arms 12, 12' of this linkage are connected by joints 15, 15 to the piston rods of the pressure cylinder, namely, as will be seen, a pressure cylinder with two pistons operating in opposition to one another. At their other end they are mounted slidably on bar projections 16, 16'. The arrangement of the pressure device is pivotal on both sides and permits adequate movement in all directions and secures the said pressure device against any eccentric stresses.

FIGURE 6 also shows in a preferred embodiment the combination of the pivot pins of two adjacent hydraulically operated bars to form a continuous pin, so that a common pivot acting in such manner as to align and give mutual supporting of the two bars is obtained and, for example, is provided by connecting together the pins 14, 14 by way of a tubular centre piece 17.

FIGURE 7 diagrammatically illustrates another possibility of allowing the operating cylinder, a double piston cylinder 6" in this case, to act centrally on the locking elements out of alignment with said elements, while avoiding any harmful stresses on the cylinder.

It will be seen that in this case the double piston cylinder 6 is mounted in two guide sleeves 18, 18 which by the action of the pressure pistons of said cylinder can be slid away from and towards one another. These sleeves, one of which, 18, is connected to one piston rod by means of the pin 19 and the other 18' to the other piston rod by means of the pin 19', form the linkage which transmits the cylinder force through the projection 20 and 6 the joint 21 to the locking element 2 and through the projection 20' and the joint 21' to the locking element 2.

All the embodiment described propose pivotal readily detachable connections between the piston rods and the locking elements, which is so constructed that they enable one or other locking element to be changed in a very simple manner, such changing being frequently necessary in some cases.

It may prove advantageous to give the jointly operated locking elements, as shown in FIGURE 5, another guide in addition to the guidance given to them by the accommodating aperture of the bars, this further guidance being in the form of projections 10 or cross-members 11 which bridge the space between the two bars.

FIGURE 8 shows simply in a diagrammatic view the inter-dependent operation of two bars which are cantilevered from a support stand and the locks of which have locking elements movable in opposite directions, and the advancing cylinder for the stand.

In this figure, reference numeral 22 denotes the supply conduit for the pressure medium, which is delivered from any desired pressure medium source, to a valve 26 from which three branch conduits 24, 25 and 27 originate.

At 28 the conduit 24 branches into the conduit 31 which leads to the cylinder space 29 of the advancing cylinder 30, and the conduit 33 which leads to the operating cylinder 32 for the locking devices, and which opens into the space between the two pistons 35, 35", which are disposed in the cylinder 32 and move in opposite directions. The conduit 27, which branches: into the conduits 2'7, 27 serves to return the pressure fluid during the bar lowering phase. These conduits 27', 27 lead into bores 36, 36 of the piston rods of the pistons 35', 35".

At its two ends, the cylinder 32 is enclosed by guide sleeves 37, 37", which are slidable thereon and the bars of which are joined fast to the piston rods 38', 38", so that by the movement of these piston rods the two guide sleeves 37, 37" are mechanically moved and during this drive the locking elements 39', 39" fastened on them. The conduits 27, 27 are connected to bores in the heads of the guide sleeves.

The shifting of the ducts through which the pressure medium is discharged during the bar lowering phase, to the bores 36', 36" of the piston rods enables the end re gions of the cylinder spaces 40', 40 to be operated in the twin arrangement illustrated.

Reference numeral 41 in FIGURE 8 is intended only to represent diagrammatically the conveyor which in known manner is connected to the piston rod of the piston 42 of the advancing cylinder 39 and which, according to the exemplified embodiment, forms the fixed point enabling the supporting device to be advanced.

The mode of operation of the hydraulic circuit illustrated will be immediately apparent, namely that on the opening of the valve 26 the hydraulic pressure through the conduit 24 first passes through the branch conduit 33 in the space between the pistons 35', 35", which have the lighter work to perform, and acts on these pistons, so that the locking elements 39, 39 are moved apart out of their position corresponding to the maximum angle of the bars, and the bars drop, whereupon after completion of this process the full pressure becomes operative on the piston 42 of the advancing cylinder by way of the conduit 31 so that this cylinder, as a result of the reaction, moves in the direction of the arrow and draws after it the support stand which is connected rigidly to it.

FIGURE 9 is a partial view of the embodiment of a supporting device having a bar which is carried thereby and which, according to the invention, is adapted to be swung up and, in the swing-up position, locked, and with an operating cylinder disposed in the longitudinal direction of the bar.

FIGURE 10 is a section on the line lit-10 in FIG- URE 9.

FIGURE 11 is a modified embodiment of the locking element in comparison with FIGURE 9.

In these figures reference 41 denotes a prop of the supporting device, for example a support stand, which consists of the double arrangement of prop and bar without any forward transverse connection, while reference 42' denotes a bar carried thereby.

According to the exemplified embodiment, an intermediate bar 44 is mounted on the bar 42 or in the interior of the section thereof, and is extensible by means of the cylinder 43 and at its end carries the substantially U-shaped pocket 45 welded to the section of the bar 4-4. The side cheeks 46, 46 of this pocket have apertures 47, 47" which are in line with one another and which according to the exemplified embodiment have the form of an upright rectangle. The advance bar 49, which is symmetrical with respect to its longitudinal axis and which can thus be used in both positions, is articulated on the pocket so as to be pivotal about a pin 48 passing through the pocket cheeks. Said bar is distinguished in that it has a deliberately weakened zone in its central region, by means of whose deformation, elastic at first and then plastic, its pressure stresses can be taken. According to the exemplified embodiment, its front end has a widened replaceable part 50, which is adapted to pivot with respect to the bar axis and which can be adjusted in the longitudinal direction.

Pivoting of the bar 49 about the pin 48 is effected by means of the wedge 51 which extends in the longitudinal direction of the bar and which is operated by the hydraulic or pneumatic pressure cylinder 52 which according to the exemplified embodiment is disposed, namely, as shown at 53, articulated, directly beneath the projecting part of the supported bar 42.

The piston of this pressure cylinder is also pivotally connected to the wedge 51 at 54 and in the arrangement il- *lustrated .acts so as to lift the bars when it is extended and lower the bars when it is retracted. The arrangement of the wedge and hence its directions of movement may also be the reverse, as shown by chain-dotted lines in FIGURE 9. The movements of the wedge in the case of the exemplified embodiment are transmitted forwardly of the pivot pin 48 to the undersurface of the bar 49 by means of the rider element 55, which is guided in the apertures 47, 47" in the pocket and which has a correspondingly bevelled bottom surface and the top surface of which, as clearly shown in FIGURE 9, bears against the bottom surface of the bar 49 while forming a comparatively large effective lever arm, this being rendered possible by appropriate construction of the Pocket 45.

The rider element 55 is preferably of hollow construction, for example has a longitudinal bore 56, so that if a pre-determinable load is exceeded, such load being above the limit at which plastic deformation of the weakened region of the bar 49 occurs, it can yield.

By these steps which are adapted to one another and to the work of the pressure cylinder the possibility of action of the cylinder is ensured even under unusual load conditions of the advance bar.

FIGURE 11 shows a particularly advantageous embodiment of the rider element which also is intended to give good adaptation of its operative pressure surfaces to the cooperating surfaces. According to this embodiment, the rider element consists of two halves 55', 55", which are symmetrical with respect to its longitudinal axis and the facing surfaces of which are shaped to constrict to correspond to the periphery of a cylindrical roller 57 disposed therebetween, so that the component elements may now be given working surfaces which both cooperate with the co-acting surfaces in a plane relationship, instead of the otherwise necessary curved construction of the top surface as shown in FIGURE 9. The pressure-resilient construction of the rider element is only a preferred construction, i.e., it is not absolutely essential.

In FIGURE 9, the possibility of arranging the pressure cylinder 52' in the interior of the intermediate bar 44 is shown in chain-dotted lines for the case when the said intermediate bar 44 is a hollow element of appropriate dimensions.

With this embodiment, a sleeve 58 which is joined fast to the piston rod on the cylinder 52 but which is secured so as to be non-slidable on the bar is fitted on the cylinder 52 and in it acts the cylinder 52' which is slidable under the action of the pressure medium flowing into the cylinder space 60' through the bores 59 in the piston rod or into the cylinder space 60' through the supply conduit 59. The cylinder in turn carries a projection 61 by which it acts on the wedge 51 by engaging through a slot in the elements 43 and 44, if required with the interposition of a joint permitting a certain amount of .play. Otherwise there is no change to the fundamental arrangement.

The possibility of abandoning the wedge and making the rider element expansible and operating the cylinder 52 is not shown in the drawings. This could be embodied, for example, by making the roller 57 of FIGURE 11 with an appropriate increase of its periphery as an eccentric element which is rotated so as to swing the bar up or down, by way of a lever arm disposed on the said eccentric element and ope-rated by the cylinder 52.

When the support unit is equipped, as shown in FIG- URE 9, with an intermediate bar which is slidable by means of a special hydraulic cylinder and to which in this case the bar 49 is connected, then this cylinder and the cylinder for operating the wedge are connected together, if required so as to act in dependence on one another as to time. The combination of the hydraulic system of the operating device for the locking elements with the hydraulic advancing cylinder in the manner described above may also be effected equivalently with the arrangement shown in FIGURES 911.

FIGURES 12 and 13 are respectively a side elevation and plan view of the possibility already indicated herein- .above of embodying the invention in such manner that an intermediate bar which at its coal-face end has a widened part constructed in the form of a casing is first articulated on a support stand and on the underside of the widened part is supported by a special prop which advances in the same rhythm as the support stand. In this case, the advance bar which is swung up and down in the manner described by hydraulic operation -of the locking element is connected to the intermediate bar inside the casing.

The locking cylinder which is also disposed to be detachable in this exemplified embodiment is mounted rearwardly of the wedge with clearance in a cavity in the widened end of the intermediate bar in accordance with the fundamental embodiment shown in FIGURE 2, lefthand part.

In these figures reference 62 denotes the intermediate bar which is articulated on a cross-member 64, which connects two bars at 63' and 63" carried by a support stand 65, in any manner known per se, but with the provision of a clearance which also permits limited pivoting movements about the longitudinal axis of the intermediate bar.

The coal-face end of this bar, which is supported by the prop 66, forms, by means of the plates 67 and 67' welded to the lock part of the bar, the casing-like widened part from which the actual advance bar is cantilevered. This easily de-coupled bar which, after any deformation, can be cantilevered again equally easily in a position turned through is tape-red in its main .part like the cantilever bar according to FIGURE 9 and like the latter carries a fitting in the form of a plate 70, which establishes contact between the bar and the roof over a larger surface and which is movable in all directions.

A plate 68 of the same kind movable in all directions may also be fitted on the narrow part of the intermediate bar 62.

The locking cylinder 71 forming an independent structural part is situated transversely of the longitudinal direction of the bar and acts by its piston rod on the projection 72 of the bolt-like transverse wedge 73 which effects the upward and downward swinging movements of the advan-cebar 69.

' This arrangement particularly advantageously gives the possibility of dividing up into component parts of relatively small weight a wide bar which would otherwlse be used and which would extend rigidly from the cross-member 64 to the coal-face edge of the plate 70, and the assembly of which would entail considerable difficulties and risks in some cases owing to the considerable bulk and large weight, while excellent automatic adjustment to the roof is obtained, and if necessary these component parts can be lifted and fitted on the supporting device by ust one man.

The invention is not limited to the embodiments which have been described hereinabove in detail nor to the simultaneous use of all its elements, and some of these, for example the construction of the rider element, and the hydraulic circuit described hereinbefore, may advantageously be used in other combinations.

Thus although not equally advantageous or while accepting other disadvantages, it is possible for the longitudinal wedge disposed in the pocket to be inserted in the transverse direction with appropriate adaptation of the pocket and rider, and to use an opposed arrangement of the wedge of the second cantilever bar of a double frame for operation by means of a double cylinder, and if required, this cylinder combination can be applied to a pair of support frames carried by one stand.

In the embodiments illustrated in the accompanying drawings it will be understood that in the event it is desired to impart more pressure to the roof support bar in one direction of movement of the associated piston than the pressure applied in the opposite direction of movement of the piston, the piston can be provided with two piston faces. In such an arrangement the one of the piston faces is effectively operative in one direction of movement thereof, while the other is effective in the opposite direction.

I claim:

1. A mine roof supporting device comprising:

a first pair of laterally aligned and interconnected spaced bars;

a second pair of laterally aligned and interconnected spaced bars; means for pivotally connecting one end of each of the bars of said first pair respectively to one end of each of the bars of said second pair, said means providing for hinging movement between said first and said second pair of bars about an axis extending transversely to the longitudinal axes of the bars;

shiftable locking means for effecting uni-directional locking of said first pair of spaced bars with respect to said second pair of spaced bars, said locking means and said one end of each of the bars of said second pair including cooperating engageable relatively movable surfaces, one of which is inclined with respect to the other; and

fluid pressure operated actuating means interconnected to and for effecting shifting movement of said locking means, said actuating means including double acting cylinder piston means, said cylinder and piston means being movable under the effect of pressure fluid to shift said locking means in opposite directions, whereby when said locking means is shifted in one direction the cooperating engageable surfaces cause the bars of said second pair to be pivoted up wardly and restrained against downward deflecting movement about said transversely extending axis and when said locking means is shifted in the opposite direction the bars of said second pair are pivoted downwardly and restrained against upward deflection about said transverse axis.

2. A device according to claim 1, wherein said piston has two piston faces, one of said piston faces is effective to cause relative movement of said cylinder and piston in the other of said piston faces is effective to cause relative said one direction so as to shift said locking means and movement in said opposite direction so as to shift said locking means in an opposite direction, said other piston face being larger in area than said one piston face.

3. A device according to claim 1, wherein said fluid pressure operated actuating means is detachably mounted on said locking means.

4. A device according to claim 1 including fluid pressure operated advancing means for effecting advancing movement of the mine roof supporting device, said fluid pressure operated advancing means including double acting cylinder piston means connected to a common source of fluid pressure with the double acting cylinder piston means of said fluid pressure operated actuating means, the pistons of said cylinder piston means having piston faces, the areas of said piston faces being so related that the double acting cylinder piston means of said actuating means is operated to cause the bars of said second pair to be pivoted downwardly before the double acting cylinder piston means of said advancing means is operated.

5. A device according to claim 1, wherein said locking locking means includes a locking element for each pair of pivotally connected bars, said locking elements being mounted for movement axially in opposite directions.

6. A device according to claim 5 wherein said actuating means includes a pressure cylinder, two pistons working in said cylinder, and means connecting each piston to one of said locking elements such that said locking elements are moved simultaneously in opposite directions to one another to effect pivotal movement of the bars of said second pair with respect to the bars of said first pair.

7. A device according to claim 5, wherein said actuating means includes a pressure cylinder and a piston working in said cylinder and connected to each of said locking elements.-

8. A device according to claim 7, wherein said piston and cylinder are connected respectively to one and the other of said locking elements to move said locking elements in opposite directions relatively to one another durlng relative movement of said piston and cylinder.

9. A device according to claim 7, including a piston rod for said piston and a lever linkage interconnecting said piston rod to one of said locking elements. 10. A device according to claim 7, wherein said lockmg elements are mounted for movement in the same direction, and said cylinders and pistons are mounted co-axially with their common axis parallel to the direction of movement of said locking elements.

11. device according to claim 7, wherein said pivotal means includes a single pivot pin extending transversely of said pivotally connected bars.

12. A device according to claim 1, wherein said cylinder and piston means are mount-ed to extend in th axial direction of said pivotally mounted bars.

13. A device according to claim 1, including a guide sleeve relatively to which said cylinder is slidable, said guide sleeve being connected with said piston and said cylinder being operatively connected with said locking means.

14. A device according to claim 1, including an intermediate element interconnecting said cylinder means and said locking means, said intermediate element being deformable under pressure in excess of a certain limit and being arranged to bear upwardly against said pivotally mounted bars.

15. A device according to claim 14, wherein said pivotally mounted bars have a weakened deformable portion.

16. A device according to claim 14, wherein said intermediate element comprises two relatively pivotal members.

17. A device according to claim 1, including at least one other extensible bar pivotally mounted with said second pair of bars.

18. A device according to claim 17, wherein said second pair of bars includes a weak portion being provided therein, said weak portion being deformable at a pressure in excess of a critical value, and said pivotal means connecting said bars including a second weak portion such that said pivotal means are deformable at a pressure in excess of a critical value which is greater than said firstmentioned value.

19. A device according to claim 17, including a bearing plate pivotally mounted on said extensible bar to engage a mine roof, said plate being capable of adapting itself to the inclination of said roof.

References Cited by the Examiner UNITED STATES PATENTS 1,469,360 10/1923 Cullen 279-121 X 12 2,749,712 6/1956 06116611 61-451 2,780,067 2/1957 Jacobi et al 61 45.1 2,884,272 4/1959 Rutkowski 6145.1 X 2,959,924 11/1960 Groetschel 61-45.l

5 FOREIGN PATENTS 588,111 6/1957 Belgium.

OTHER REFERENCES German printed application No. 1,027,159, Apr. 3, 10 1958 (K1. 5c 10/01). (Corresponding British, 834,976,

May 18, 1960.)

CHARLES E. OCONNELL, Primary Examiner.

15 JACOB L, NACKENOFF, Examiner. 

1. A MINE ROOF SUPPORTING DEVICE COMPRISING: A FIRST PAIR OF LATERALLY ALIGNED AND INTERCONNECTED SPACED BARS; A SECOND PAIR OF LATERALLY ALIGNED AND INTERCONNECTED SPACED BARS; MEANS FOR PIVOTALLY CONNECTING ONE END OF EACH OF THE BARS OF SAID FIRST PAIR RESPECTIVELY TO ONE END OF EACH OF THE BARS OF SAID SECOND PAIR, SAID MEANS PROVIDING FOR HINGING MOVEMENT BETWEEN SAID FIRST AND SAID SECOND PAIR OF BARS ABOUT AN AXIS EXTENDING TRANSVERSELY TO THE LONGITUDINAL AXES OF THE BARS; SHIFTABLE LOCKING MEANS FOR EFFECTING UNI-DIRECTIONAL LOCKING OF SAID FIRST PAIR OF SPACED BARS WITH RESPECT TO SAID SECOND PAIR OF SPACED BARS, SAID LOCKING MEANS AND SAID ONE END OF EACH OF THE BARS OF SAID SECOND PAIR INCLUDING COOPERATING ENGAGEABLE RELATIVELY MOVABLE SURFACES, ANE OF WHICH IS INCLINED WITH RESPECT TO THE OTHER; AND FLUID PRESSURE OPERATED ACTUATING MEANS INTERCONNECTED TO AND FOR EFFECTING SHIFTING MOVEMENT OF SAID LOCKING MEANS, SAID ACTUATING MEANS INCLUDING DOUBLE ACTING CYLINDER PISTON MEANS, SAID CYLINDER AND PISTON MEANS BEING MOVABLE UNDER THE EFFECT OF PRESSURE FLUID TO SHIFT SAID LOCKING MEANS IN OPPOSITE DIRECTIONS, WHEREBY WHEN SAID LOCKING MEANS IS SHIFTED IN ONE DIRECTION THE COOPERATING ENGAGEABLE SURFACES CAUSE THE BARS OF SAID SECOND PAIR TO BE PIVOTED UPWARDLY AND RESTRAINED AGAINST DOWNWARD DEFLECTING MOVEMENT ABOUT SAID TRANSVERSELY EXTENDING AXIS AND WHEN SAID LOCKING MEANS IS SHIFTED IN THE OPPOSITE DIRECTION THE BARS OF SAID SECOND PAIR ARE PIVOTED DOWNWARDLY AND RESTRAINED AGAINST UPWARD DEFLECTION ABOUT SAID TRANSVERSE AXIS. 